I have compiled open-mpi 1.4.2 and uses them with boost-mpi. I can
compile and run my first example. If I run it without mpiexec
everything works fine. If I do it with mpiexec -np 1 or 2 I would get
messages like:

[node:05126] [[582,0],0] ORTE_ERROR_LOG: Error in file
ess_hnp_module.c at line 230
--------------------------------------------------------------------------
It looks like orte_init failed for some reason; your parallel process is
likely to abort. There are many reasons that a parallel process can
fail during orte_init; some of which are due to configuration or
environment problems. This failure appears to be an internal failure;
here's some additional information (which may only be relevant to an
Open MPI developer):

....
[node:05125] [[581,0],0] ORTE_ERROR_LOG: Error in file orted/
orted_main.c at line 325
[node:05124] [[INVALID],INVALID] ORTE_ERROR_LOG: Unable to start a
daemon on the local node in file ess_singleton_module.c at line 381
[node:05124] [[INVALID],INVALID] ORTE_ERROR_LOG: Unable to start a
daemon on the local node in file ess_singleton_module.c at line 143
[node:05124] [[INVALID],INVALID] ORTE_ERROR_LOG: Unable to start a
daemon on the local node in file runtime/orte_init.c at line 132

....
--------------------------------------------------------------------------
*** The MPI_Init() function was called before MPI_INIT was invoked.
*** This is disallowed by the MPI standard.